Device for redirecting objects having different masses

ABSTRACT

An apparatus for selective diversion of objects such as containers, packing and packing units of different mass. The apparatus has a first transport device for the objects and a diversion device for diverting predetermined objects from the first transport device onto a second transport device. The intensity with which the objects are diverted from the first transport device onto the second transport device is controlled by means of a controlled device.

The invention relates to an apparatus for selective diversion of objectssuch as containers, packing, packing units of different mass. Theapparatus has a first transport device for the objects and a diversiondevice for diverting predetermined objects from the first transportdevice onto a second transport device. The intensity with which theobjects are diverted from the first transport device onto the secondtransport device is controlled by means of a control device.

Such diversion apparatuses are used to divert faulty objects, e.g.containers which are not completely full, from a flow of such objects.

From WO 00/68120 (=DE-U-299 08 036) it is known to control the intensitywith which objects are diverted in such a way that the objects receive adiversion impulse of differing strength transversely to their directionof transport and thus reach one of several second transport devicesrunning parallel alongside each other.

A similar apparatus is known from DE-A-100 07 627 in which uprightbottles are diverted by means of a single impulse of a pusher, whilehorizontal bottles are diverted by means of an impulse sequence of thepusher.

An apparatus for sorting out faulty packaging units is known fromDE-C2-36 23 327, the angle at which the pusher pushes the packagingunits from the conveyor belt being automatically controlled. The angleis set depending on the transport speed of the conveyor belt and thevector perpendicular to it of the required pushing speed.

An apparatus for sorting out faulty packaging units, in particularbottles, is known from DE-C1-37 34 599, the pusher being driven by a camand developed as a slide plate to which a brushing segment is attached.The acceleration and the speed of the slide during the sorting-outprocess are determined by the shape and the speed of rotation of thecam. It is to be thereby achieved that the path by which the packagingunits to be sorted out are pushed is independent of the degree offilling of the packaging units.

Diversion devices have a diversion element, displaceable transversely tothe direction of transport, which is driven pneumatically or by electricmotor. The diversion element can also be in an air jet which pushes anobject to be diverted transversely to the direction of transport. In thecase of diversion apparatuses in which objects of different mass are tobe diverted onto a second transport device, there is the difficulty thatlight objects are more markedly accelerated by the diversion device andthereby obtain a higher speed component transversely to the direction oftransport than heavier objects.

The object of the invention is to create a diversion apparatus whichimparts a transverse impulse to objects regardless of their mass andwhich leads to a roughly equally wide displacement of the objectstransversely to the direction of transport.

This object is achieved according to the invention by a device forestablishing the progress of the diversion of an object, the controldevice activating the diversion device more strongly or for longerdepending on the established progress if the progress is less, or viceversa.

Due to their greater mass heavy objects initially have a smaller speedcomponent transversely to the direction of transport from the diversionelement. The progress of the diversion is monitored by means of a sensorfor example by measuring the period of time that the diversion elementor the object to be diverted requires in order to reach a certain pointof its diversion movement. When the sensor reports that this period oftime is over a certain value the diversion device is activated morestrongly for the remainder of the diversion movement, i.e. in the caseof a pneumatic diversion device the diversion element is extended with ahigher pressure or further and in the case of a diversion element drivenby electric motor the voltage of the electromotor drive is increased orapplied for a longer period. In the case of a diversion element in theform of an air jet, the nozzle pressure is increased or likewise appliedfor a longer period.

In another embodiment the speed reached by the diversion element at acertain point in time after the start of the diversion process ismeasured. An angle transmitter, a linear encoder, a speedometer or anacceleration indicator can be used for this. The basic idea is in eachcase that a heavier object requires more time for the predeterminedsection or has reached a lesser speed than a lighter object, so that thediversion device has to be activated correspondingly more strongly orfor longer.

The diversion device can also be controlled by integrating in thediversion element a force sensor which measures the force with which thediversion element presses against the object. An object of greater masswill offer greater resistance to the diversion element, so that a higherforce is measured.

In the case of a diversion element driven by electric motor the powerconsumption can also be used as a criterion.

Depending on the established progress the diversion device is activated,the activation being greater or for longer for a lesser progress andvice versa. Thus if a relatively low speed or a long extension time isascertained at a predetermined point, the diversion device is activatedmore strongly or for longer. In the case of a pneumatic drive of thediversion device e.g. the pressure supplied to the cylinder is increasedor the diversion element is further extended, i.e. the object isaccelerated for a longer period by the diversion element transversely tothe direction of transport. Correspondingly in the case of a drive byelectric motor the supplied power is increased or the diversion processis prolonged.

The diversion apparatus according to the invention can also be used todivert objects of different mass from a first transport device onto oneof several second transport devices. The further away from the firsttransport device the concerned second transport device is, the morestrongly must the diversion device be activated, the activationadditionally taking place according to the invention corresponding tothe mass of the object.

The diversion apparatus according to the invention is suitable inparticular for transport units in which the objects are transported pastthe diversion element at a very small distance of at most a fewmillimetres. The distance is to be particularly small compared to thelength of the diversion movement of the diversion element. If thedistance is greater, e.g. 2 cm, the diversion apparatus according to theinvention can also be used for stable objects, such as beer crates ormineral-water crates if the distance is at least always the same.

An embodiment of the invention is explained below with reference to thedrawing. There are shown in:

FIG. 1 the diversion device from above in the resting position;

FIGS. 2 and 3 the diversion device of FIG. 1 at different times during adiversion process; and

FIG. 4 the chronology of a diversion process.

A diversion device 10 is arranged next to a first conveyor 11 which is alink chain conveyor. The first conveyor 11 conveys an object 14, whichis a beer crate in the represented example, past the diversion device10. The diversion device 10 serves to push certain objects 14, e.g. notcompletely filled beer crates, from the first conveyor 11 onto a secondconveyor 12 running parallel alongside it and thus exclude them from thefurther production process.

The diversion device 10 contains a diversion element 16, which can beswivelled by means of a swivel arm 18. The diversion element 16 is aplate aligned in the direction of transport, and the swivel arm 18 isdesigned so that the alignment of the diversion element 16 is maintainedupon swivelling out. To this end the swivel arm 18 consists of a mainlever 19 and a parallel lever 20.

The pivot points 21 of the main lever 19 and of the parallel lever 20are arranged vis-à-vis the diversion element 16 at a distance in thedirection of transport indicated by the arrow 22, so that, uponswivelling out, the diversion element 16 moves at the same time roughlyin the direction of transport. The object 14 is thus pushed essentiallytransversely, upon swivelling out of the diversion element 16, on thefirst conveyor 11, without a greater relative movement in the directionof transport taking place between the object 14 and the diversionelement 16.

The main lever 19 is roughly T-shaped and is coupled at the bottom endof the vertical T-column in the pivot points 21. In the startingposition shown in FIG. 1 the vertical T-column lies roughly counterparallel to the direction of transport 22. The diversion element 16 iscoupled at the end of the horizontal T-bar pointing towards the firstconveyor 11, while a swivel cylinder engages at the end pointing awayfrom the first conveyor 11. A sensor 30 is arranged at a small distancefrom this end of the horizontal T-bar. The sensor 30 produces a triggersignal when the end of the T-bar moves past it. This trigger signal isproduced if the parallel lever 18 has swivelled by roughly 2° whichcorresponds to an extension section of the diversion element 16 ofroughly 17 mm (FIG. 2).

The period of time t which passes between the triggering of the swivelcylinder 28 and the occurrence of the trigger signal serves as a measureof the mass of the object 14. The longer this period of time t, thegreater the mass of the object 14. The length of the trigger time T ofthe swivel cylinder 28 is controlled according to this period of time tby means of a control device 32. There are three gates lying one behindthe other for the period of time t. If the period of time t falls withinthe range of the first gate G1, trigger time T1 is chosen. If the periodof time t falls within the range of the second gate G2, trigger time T2which is greater than T1, is used. If the period of time t falls withinthe third gate G3, then trigger time T3 which is greater than T2, ischosen (FIG. 4).

The trigger times T are established experimentally and taught to thecontrol device 32. In the represented embodiment the trigger time T iscontrolled stepwise. However, it is preferably controlled continuouslyvia a characteristic line. For this, several points of thecharacteristic line are established experimentally and the curvesections lying in between are interpolated.

When experimentally establishing the trigger times T or thecharacteristic line, the influence of the differing friction of heaverand lighter objects can be taken into account.

List of Reference Numbers

-   -   10 diversion device    -   11 first conveyor    -   12 second conveyor    -   14 object    -   16 diversion element    -   18 parallel lever    -   19 main lever    -   20 auxiliary lever    -   21 point of rotation    -   22 direction of transport    -   28 swivel cylinder    -   30 sensor    -   32 control device

1-7. (canceled)
 8. An apparatus for the selective diversion of objectsof different mass, the apparatus comprising: a first transport device; asecond transport device adjacent to the first; a diversion device fordiverting a selected object from said first transport device onto saidsecond transport device; a sensor for determining a measurement ofprogress of the diversion of the selected object has been diverted; anda diversion device controller connected to the sensor, whereby thediversion device controller adjusts the intensity with which thediversion device diverts the selected object from the first transportdevice to the second transport device.
 9. The apparatus of claim 8,wherein the intensity with which the diversion device diverts theselected object from the first transport device to the second transportdevice is a function of a period of time required for at least one ofthe diversion device and the selected object to cover a predeterminedpath.
 10. The apparatus of claim 8, wherein the intensity with which thediversion device diverts the selected object from the first transportdevice to the second transport device is determined by measuring thetime required for a portion of the diversion device to attain at leastone of a certain speed and acceleration measurement.
 11. The apparatusof claim 10, wherein the intensity of the diversion is established by atleast one of a group comprised of an angle transmitter, linear encoder,a speedometer or an acceleration indicator.
 12. The apparatus of claim10, wherein the intensity of the diversion is established by a forcesensor which measures the force required to move the selected object.13. The apparatus of claim 8, wherein the diversion device ispneumatically driven.
 14. The apparatus of claim 8, wherein thediversion device is driven by an electric motor.
 15. The apparatus ofclaim 8, wherein at least one of the intensity and duration of theactivation of the diversion device is controlled by reference to acontinuous characteristic line depending on a given period of time. 16.The apparatus of claim 8, wherein the selected object is transported onthe second transport device for a small distance past the diversiondevice.
 17. The apparatus of claim 12, wherein a measure of intensitywith which the diversion device diverts the selected object from thefirst transport device to the second transport device is established bymeasuring the power consumption.
 18. A method for selective diversion ofobjects of different mass from a first transport device onto a secondtransport device adjacent to the first transport device, the methodcomprised of the steps of: diverting a selected object from the firsttransport device onto the second transport device; measuring theprogress of the diversion of the selected object; comparing the progressof the diversion of the selected object with a standard progress ofdiversion; and adjusting the intensity with which the selected object isdiverted from the first transport device onto the second transportdevice.